Method of making an artist&#39;s mat



Aug. 22, 1933. A, B GLENN 1,923,483

lMETHOD oF MAKING AN ARTIsTs MAT Original Filed Dec. 7, 1927 Ari/z zzf 5 Glenn.

atented ug. 22, 1933 UNirED STATES PATENT OFFICE@ l 1,923,483 METHOD oF MAKING AN ARTIs'rs MAT Arthur B. Glenn, LosAngeles, Calif.k

Original application December 7, 1927, Serial No. 238,410. Divided and this application April 2, 1930. Seria/l N0. 441,036

This invention relates generally to printing and ywhich will enableit to he used directly in a more particularly to stereotyping. K stereotype mold. y 1 Y According to methodsv now generally in use, One of the ooiects ofthe invention is to pro` in preparing a stereotype, itis necessary forthe vide a method which will avoid the use of metal 5 artist to prepare a drawing on paper. Usually in producing the mat. .l 6,0,` a photograph must be` made from this drawing, It is sometimes desired to send engravingsgto and an engraving or a matrix is formed theredistant points through the mail or by express. after from which the print or stereotype is pro'- The matrix prepared according to my invention duced. can be readily sent through the mailslwithout It has been attempted heretoforev to prepare danger of injury and it is one of the yobjects G5 a matrix for stereotyping by having the artist of the invention to producea method which will draw directly upon a metalplate having a facing meet this requirement. Further objects of the consisting of a layer of chalk. According to this invention will appear hereinafter. method, the artist etched the facing with a sharp The present application is a division of my stylus, thereby producing a matrix which could former application, Serial No. 238,410, filed De- 7,0., be used in producing a stereotype. n cembcr 7, 1927. l. In etching upon this mat the pointA of the stylus The-invention consists in the novel steps and of course, in forming a line, penetrated through combination of steps in the method to be dethe entire depth of the facing, down to the scribed hereinafter, which steps cooperate to backing sheet `of metal. When in the mold the produce an efficient method for forming a mat type metal fiowed into these engraved lines and Suitable for forming a matrix. the face of the metal plate backing sheet deter- A preferred embodiment of the invention is de- Vmined the position of the printing faces of the scribed in the following specification, and the stereotype corresponding to the engraved lines. broad scope of the invention is pointed outin r This method has been found unsatisfactory for the appended claims. f SQ the reason that the metal plate is a conductor of In the drawing; heat and chills the molten metal rapidly, leav- Figure 1 is aside elevation illustrating the first ing an inefficient and chilled face on the stereostep in the production of the mat. type, and also because the chalk and composi- Figure 2 is a side elevation illustrating the mat tions heretofore used to form the facing of the at a further stage inits manufacture; thisview S5 mat have been found to be brittle. Due to the particularly illustrates the finishing of the mat fact that a metal plateY makes a poor backing to the desired thickness. f sheet, chilling rapidly, and to the brittleness of Figure 3 is a cross-section through the comthe chalk, it is impossible for the artist to prou pleted mat. duce a clean, unbroken line. Heretofore no ma- Figure 4 isa vertical section through a mold- -99 terial has been discovered suitable for makingl ing box and illustrating the manner' in which the facing of such a mat. Such a facing must be the matrix is employed in forming the stereosoft enough to permit the artist to draw uponv it type; and readily without cracking off on the edges of the Figure 5 is an illustration showing, as an exlines formed by the stylus, and furthermore, the ample, a character of print that can be produced facing must be sufficiently. elastic to prevent it from a stereotype manufacturedl in accordance from forming cracks when handled, shipped, or with my invention. Y when kept in stock for indefinite periods. The Beforeproceeding to a detailed descriptiony of material forming the facing mustalso resist the thisinvention, it should be .stated that the pres temperature and weight ofthe type metal when ent appHCatOn iS a dVSiOIl 0f 'my pending pi flowed over it in the mold. vplication Serial No.` 238,410 filed Y'December 7,k

The general object of this invention is to pro- 1927. Y vide a method which-will enable the artist to In platng the invention, I prefer t0 employ produce a matrix directly,` Vthereby eliminating Va backing sheet which is in the form of a dense, steps now necessary in theusual methods of propressed paper board. A suitable board ,for thisr ducing stereotypes. One of the objects of the .purpose is sold in the market under the name f invention is to produce an eient method to of Vehisote orl Masonite, or pressed wood board. be used informing a mat upon which the artist The backing sheet must have certain properties may draw or etch directly to produce a matrix Which are importanJG as affecting the Chalatel' and enabling the mat to have characteristics of the printing face of the stereOtyDe- In Chis-110 ybacking sheet or scratch the face of the backing sheet. In other words, the Vface of the backing sheet which carries the facing of my composition should be hard and resistant to the action of the stylus. I donot use a rnetalbacking sheet for the reason that casting metal directly against metal has a tendency to chill'the stereotyping metal and mars the printing face vof the stereotype formed; also such a backing sheet tends to expand from the heat in the mold and produces buckling or bulges in the matrix which interfere with fthe production of perfect stereotypes. I have found that the paper backing sheet described effectively carries the facing Aand at the same time resists the temperature of the type metal when flowed onto it in the mold, maintaining the heat of the metal and producing perfect reproductions.

In the drawing, 1 indicates a backing sheet of paper board of the character suggested above. In preparing this backing sheet, I prefer to dress it down to a thickness of about le after which I coat the faces of the sheet with shellac, using, however, just suflicient shellac to be absorbed by the surface of the board. This produces al smooth faceon the board and admirably adapts it 'to produce a clean printing face forthe stereotype. The composition which I prefer to use to form the facing for the mat is a mineral earth and preferably is composed substantially or principally of magnesium-silicate. For thispurpose,

I prefer to employ' purified talcum powder. In

preparing the composition, I` mix together certain ingredients, including substantially one part of ground glue by measure to eight parts of water by measure. To this I add about twoY ounces of yellow Diamond Dye for each gallon of the glue and water. The Diamond Dye is included as Va coloring and to give a smoother texture to the composition.V In orderl to increase the preserving qualities, I prefer to add a few drops of crude carbolic acid. Il mix the above ingredients witha quantity of the base or purified talcum powder insuch quantities as to .form a batterlike mixture of approximatelythe consistency of soft mud or heavy pancake batter. -In other words, I form a thin mush or thick paste from these ingredients;Vv y

On the upper face of the backingY sheet l, I heap a mass 2 of this paste (see Figure l) This should ber done to a considerable depth, prefer ably about 1/3 for a reason `which `will appear hereinafter. While the` paste is still n1oist,.I wipe onc the edge portions 3 toa point indicated bythe dotted lines in Figure 1. This leaves a a margin on the backing sheet uncovered by the paste. r z

Ir nd that in applying the paste to the backing sheet, it is necessary to take steps to insure that the'composition in the vicinity of the face of the v backing sheet will lbe densejthat is'to say, that f the particles oi the composition at this point Will be tightly packed together." This is necessary in order to insure a continuousand unpitted face inthe iinished mat; For this reason, I prefer to' jog the unfinished mat while the moist 4paste is resting upon it. This jogging settles the mass method isillustratedin Figure 5. f

2 and insures the desired density in the lower strata of the composition.

The backing sheet with the paste 2 upon it is then dried in an oven. The temperature in the oven shouldnot exceed about 250 F., and should not be sufficient to bake the paste. The function of the oven is merely to dry the paste and no boiling or baking o the paste should take place. The drying should be effected quickly. However, it .is not essential the drying be effected in an oven, and if desired, the mass can be dried in the air erin the sun providing the temperature is not permitted to rise 'too high.

When the paste has become thoroughly dry, it will be found that a portion of the liquid in the composition has risen to the upper layers of the paste, forming'a thin, hard coating, but this liquid Which operates as afbinder operates effectively to cause the dried to adhere iirmly to the face of the board; below this thin, hard coating the composition will be found to be soft and pliable, yet with its particles firmly bound together.

' t is then necessary to remove tion of the dried mass. This is accomplished by running the mat through a sander or preferably through a planer having a planer tool 4 with a plurality of knives 5 such as illustrated in Figure 2. In this operation, I prefer to dress the hardened paste 6 so as to leave a facing 7. on the backing board of approximately le" in thickness. This thickness, however, may be varied as desired to suit the special requirements of the the upper porf trade.` The planer or sander leaves a smooth,

uninterrupted face k8. If the mat'is prepared as described above, this face will be found to be devoid of pits or inequalities in its face.

The finished mat illustrated in Figure 3 is then ready to be drawn upon or etched `by the artist whouses for this purpose a stylus, hard pencil or other sharp instrument.

Ink making the drawing, however, the artist- .should take care that the point of the stylus `in making any line of the drawing penetrates com- 'type metal composition to produce a sterotype 11.

In this View the engravedlines 12 indicate how the engraving is brought down to the face of the backing sheet so as to insure a sterotype that will print perfectly. While the mat is particularly adapted for making line drawings, it is evident that by scraping away small areas of the facing of the matrix, solid black areas in the print can be produced. A good example of the character of a print that can be formed by this The glue in my composition of courseoperates as a binderand also causes the composition to adhereto the backing sheet. a

The relativelyY great depth of the paste assists in increasing the density of the composition at f the level of the face 8. Y

The mat `produced in accordance with my method need not be handled with great care, that is to say, the lfacing 7 is relatively tough and resilient, and in fact Vthe mat can bebent considerably lll() Without injury to the facing. The facing has suicient resiliency to permit this.

While the matrix described herein may be used for producing stereotypes, it also may be used in the bottom of a small mold for molding Vrubber to produce a rubber stamp. y

One of the principal advantages of the use of my invention arises from the fact that I avoid the use of a metallic backing sheet and employ a backing sheet of a material having no chilling effect upon the type material when it is run into the mold. This enables Ene and accurate reproduc` tions to be produced from the matrix.

What I claim is:

l. The method which consists in laying a paste of mineral earth on the upper face oi a flat backing sheet of paper board, drying the paste thereafter, jogging the backing sheet to condense the paste, removing the upper portion of the dried paste to form a substantially flat face and leave a relatively thin layer of relatively dense material on the backing sheet, etching the face of the backing sheet to form a matrix, and forming a stereotype in type metal directly from the matrix.

2. The method ,of making an' artists mat to y form a matrix for a stereotype which consists in forming a paste of nely divided magnesium-silicate, laying thesaid paste on the upper face of a iiat backing sheet, jogging the backing sheet and paste thereafter to increase the density in the particles of the paste nearest to the face of the backing sheet, drying the paste thereafter and then removing the upper portion of the dry paste to form a substantially iiat face on a relatively thin layer of the material.

3. The methodof making an artists'mat to form a matrix for a stereotypewhich consists in varnishing the upper face of a flat backing sheet of fibrousV material, forming a paste of finely divided magnesium silicate, laying the said paste f on the upper varnished face of the backing sheet, drying the paste thereafter, and then. removing the upper portion oi' the dried paste to form a substantially flat face on a relatively thin layer. of the material.

ARTHUR B. GLENN. 

